package com.example.kafka.consumer;

import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.KafkaConsumer;
import org.apache.kafka.common.serialization.StringDeserializer;
import org.apache.kafka.common.serialization.StringSerializer;

import java.time.Duration;
import java.util.ArrayList;
import java.util.Properties;

public class CustomConsumer1 {
    public static void main(String[] args) {

        // 0.配置
        Properties properties = new Properties();
        // 连接集群
        properties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");
        // 反序列化
        properties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
        properties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
        // 配置消费者组ID
        properties.put(ConsumerConfig.GROUP_ID_CONFIG, "test");
        // 1.创建一个消费者
        KafkaConsumer<String, String> kafkaConsumer = new KafkaConsumer<String, String>(properties);
        // 2.定义主题 test
        ArrayList<String> topics = new ArrayList<>();
        topics.add("test");
        kafkaConsumer.subscribe(topics);
        // 3.消费数据
        while (true){
            ConsumerRecords<String, String> consumerRecords = kafkaConsumer.poll(Duration.ofSeconds(1));
            for (ConsumerRecord<String, String> consumerRecord : consumerRecords) {
                System.out.println(consumerRecord);
            }
        }
    }
}
